1. Field of the Invention
The present invention relates to a fabric for a toothed belt used for a carriage feed of a copier or printer, positioning of an industrial robot, and so on.
2. Description of the Related Art
Teeth formed on a toothed belt are covered by an elastic fabric. Conventionally, in a manufacturing process, the fabric is treated with an RFL (resorcinol-formaldehyde-latex) solution to enable it to strongly bond with the teeth, and is then coated with rubber (rubberized). In the toothed belt having the fabric obtained by this processing method, however, the coated rubber adheres to or the tooth rubber exudes and is deposited on the surface of the fabric, thereby causing the frictional coefficient between the surface of the fabric and a pulley to rise, an increase in noise to occur, and rubber dust to be dispersed, because of friction with the pulley when the belt is run. Since tooth rubber includes carbon, which has a good electroconductivity, the rubber dust can cause electrical disturbances in office automation (OA) equipment and the like.
A toothed belt for preventing exudation of the tooth rubber to the fabric is disclosed in Japanese Unexamined Patent Publication (Kokai) No. 7-190150, for example. In this toothed belt, the fabric is treated only with an RFL solution, and further, a solid deposition of RFL, having 30 to 50 wt % with respect to the weight of the base cloth, is generated on the fabric.
If the solid deposition of the RFL solution is from 30 to 50 wt %, however, exudation of the tooth rubber is not sufficiently prevented. Conversely, if the solid deposition is increased, although the exudation of the tooth rubber becomes smaller, the elasticity of the fabric is impaired. Thus, it is difficult to form the teeth of the belt into the desired shape, especially in a toothed belt requiring a small pitch, such as one used for OA equipment.